How do you set mode with 'react-native start'?

[jpetersen23]

I'm trying to get Android flavors to work with the latest react-native and I can get it correctly reading mode when I run

react-native run-android --mode=productionrelease

But for the life of me, I cant figure out how to set the mode for

react-native start

as a result, when I try to open android I get an error:

Cannot locate tasks that match 'app:installDebug' as task 'installDebug' is ambiguous in project ':app'. Candidates are: 'installDevelopmentDebug', 'installDevelopmentDebugAndroidTest', 'installProductionDebug', 'installProductionDebugAndroidTest', 'installStagingDebug', 'installStagingDebugAndroidTest'.

I think its because gradle cant correctly figure out what mode I want it to run in, but reading the documentation, I cant find a way to make it work.

Older stackoverflow options had suggested hacking the cli to force it to use a custom install command, but I cant find in the CLI where that is even happening now.

https://stackoverflow.com/a/50704977

I've also found older versions of react-native that seem to have handled sending down variant, but that seems to have broken when it was switched to mode?

Here is a working example relying on variant: https://github.com/sdavid501/multiplatform

I believe I've also confirmed its not a problem with https://github.com/lugg/react-native-config by not integrating it and just doing the work of adding flavors breaks the command.

I've also made a very simple version running the following commands:
npx react-native@latest init ReactNativeConfigTestAppLatest

and then applying this patch to react flavors:

added_flavors.patch

Anyway I'm not sure where to take it at this point beyond figuring out how to hack the tool, which I'm hoping to avoid.

Thanks.

[szymonrybczak]

hey @jpetersen23 if you want to specify --mode when running Android app from watch mode (while running yarn start) → you need to provide watchModeCommandParams inside your react-native.config.js, so you need to compose something like this:

module.exports = {
  project: {
    android: {
      watchModeCommandParams: ['--mode', 'whateverYouWant'],
    },
  },
}

[jpetersen23]

Thanks @szymonrybczak that worked to get me passed the build error!

For future people who may look at my specific patch, the body of my react-native.config.js also required adding --appId to launch the right apk (if you use just a suffixId in your gradle which I didnt in my example, you can use --appIdSuffix):

module.exports = {
  project: {
    ios: {},
    android: {
      // https://github.com/react-native-community/cli/issues/2359#issuecomment-2061289989
      watchModeCommandParams: [
        '--mode',
        'developmentrelease',
        '--appId',
        'com.reactnativeconfigtestapplatest.development',
      ],
    },
  },
};

[jpetersen23]

Turns out I spoke too soon, I seem to have broken live reloading of tsx changes. Additionally when I hit r in watch mode (yarn start) I see:

warn No apps connected. Sending "reload" to all React Native apps failed. Make sure your app is running in the simulator or on a phone connected via USB.
info Reloading connected app(s)...

And nothing updates.

I confirmed the same is true if I run the commands directly as

react-native run-android --mode developmentrelease --appId com.reactnativeconfigtestapplatest.development

I also confirmed its not a debug mode thing by trying

react-native run-android --mode developmentdebug --appId com.reactnativeconfigtestapplatest.development

And that also doesnt cause it to live update again (or reload with R in the console or in the app itself).

UPDATE:

I needed to add things to the debuggable variants list.

/* Variants */
//   The list of variants to that are debuggable. For those we're going to
//   skip the bundling of the JS bundle and the assets. By default is just 'debug'.
//   If you add flavors like lite, prod, etc. you'll have to list your debuggableVariants.
debuggableVariants = ["developmentdebug", "developmentrelease"]